Objective: To identify the incidence of PAX5 deletion in childhood B-lineage acute lymphoblastic leukemia (B-ALL) without reproducible chromosomal abnormalities and to investigate the association between PAX5 abnormalities and prognosis of ALL.
Methods: Multiplex ligation-dependent probe amplification was used to determine the copy numbers of PAX5 gene in children newly diagnosed with B-ALL without reproducible chromosomal abnormalities between April 2008 and April 2013 and controls (children with non-hematologic diseases or tumors). The patients were classifiied into deletion group and non-deletion group based on the presence of PAX5 deletion.
Results: Eighteen (21%) out of 86 children with B-ALL had PAX5 deletion. The deletion group had a significantly higher total white blood cell count at diagnosis than the non-deletion group (P=0.001). The Kaplan-Meier analysis demonstrated that the deletion group had a significantly lower disease-free survival (DFS) rate than the non-deletion group (0.69±0.12 vs 0.90±0.04; P=0.017), but there was no significant difference in the overall survival rate between the two groups (P=0.128). The Cox analysis showed that PAX5 deletion was a risk factor for DFS (P=0.03).
Conclusions: PAX5 deletion is an independent risk factor for DFS in B-ALL children without reproducible chromosomal abnormalities.
目的: 初步了解PAX5缺失在无特殊重现染色体异常的B系急性淋巴细胞白血病(B-ALL)患儿中的发生情况, 并进一步分析PAX5基因缺失与ALL预后的相关性。
方法: 用多重连接探针扩增(MLPA)技术检测2008年4月至2013年4月初诊无特殊重现染色体异常的B-ALL患儿及对照组(同期非血液系统疾病及肿瘤儿童)的PAX5基因拷贝数情况。根据有无PAX5基因缺失分为缺失组和非缺失组。
结果: 86例患儿中18例(21%)发生了PAX5缺失。缺失组初诊时白细胞总数明显高于非缺失组(P=0.001)。Kaplan-Meier法分析显示:缺失组无病生存(DFS)率明显低于非缺失组(0.69±0.12 vs 0.90±0.04, P=0.017), 但两组患儿的总生存(OS)率差异无统计学意义(P=0.128)。Cox法分析显示, PAX5缺失为影响DFS的不利因素(P=0.03)。
结论: PAX5缺失为无特殊重现染色体异常B-ALL患儿DFS的独立危险因素。